Package org.apache.solr.jersey

Class NullKeyTolerantMap

java.lang.Object

java.util.AbstractMap<String,Object>

java.util.HashMap<String,Object>

java.util.LinkedHashMap<String,Object>

org.apache.solr.jersey.NullKeyTolerantMap

All Implemented Interfaces:

com.fasterxml.jackson.databind.JsonSerializable, Serializable, Cloneable, Map<String,Object>, SequencedMap<String,Object>

public class NullKeyTolerantMap
extends LinkedHashMap<String,Object>
implements com.fasterxml.jackson.databind.JsonSerializable

A Map that renders identically to a plain LinkedHashMap everywhere except through Jackson.

org.apache.solr.core.PluginInfo#writeMap groups a plugin's unnamed children (e.g. anonymous <processor> entries under an updateRequestProcessorChain) under a null key. Solr's legacy (v1) JSON response writer tolerates that null key natively, rendering it as "". Jackson, however, rejects null Map keys outright and (by default) omits null-valued entries entirely.

Wrap a config/plugin-derived map in this class to let the v2/JAX-RS (Jackson) response path render a self-describing key in place of the null key and keep null values, without changing what any non-Jackson consumer (e.g. a v1 handler reading the same map instance) sees.

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

Nested classes/interfaces inherited from interface com.fasterxml.jackson.databind.JsonSerializable

com.fasterxml.jackson.databind.JsonSerializable.Base

Constructor Summary

Constructors

Constructor	Description
NullKeyTolerantMap(String nullKeyReplacement)

Method Summary

Modifier and Type	Method	Description
void	serialize(com.fasterxml.jackson.core.JsonGenerator gen, com.fasterxml.jackson.databind.SerializerProvider serializers)
void	serializeWithType(com.fasterxml.jackson.core.JsonGenerator gen, com.fasterxml.jackson.databind.SerializerProvider serializers, com.fasterxml.jackson.databind.jsontype.TypeSerializer typeSer)

Methods inherited from class java.util.LinkedHashMap

clear, containsValue, entrySet, forEach, get, getOrDefault, keySet, newLinkedHashMap, putFirst, putLast, removeEldestEntry, replaceAll, reversed, sequencedEntrySet, sequencedKeySet, sequencedValues, values

Methods inherited from class java.util.HashMap

clone, compute, computeIfAbsent, computeIfPresent, containsKey, isEmpty, merge, newHashMap, put, putAll, putIfAbsent, remove, remove, replace, replace, size

Methods inherited from class java.util.AbstractMap

equals, hashCode, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, containsKey, equals, hashCode, isEmpty, merge, put, putAll, putIfAbsent, remove, remove, replace, replace, size

Methods inherited from interface java.util.SequencedMap

firstEntry, lastEntry, pollFirstEntry, pollLastEntry

Constructor Details

NullKeyTolerantMap

public NullKeyTolerantMap(String nullKeyReplacement)

Parameters:

nullKeyReplacement - the JSON field name to substitute for a null Map key, wherever one is found (at any nesting depth of Maps/Lists reachable from this instance).

Method Details

serialize

public void serialize(com.fasterxml.jackson.core.JsonGenerator gen,
 com.fasterxml.jackson.databind.SerializerProvider serializers)
               throws IOException

Specified by:

serialize in interface com.fasterxml.jackson.databind.JsonSerializable

Throws:

IOException

serializeWithType

public void serializeWithType(com.fasterxml.jackson.core.JsonGenerator gen,
 com.fasterxml.jackson.databind.SerializerProvider serializers,
 com.fasterxml.jackson.databind.jsontype.TypeSerializer typeSer)
                       throws IOException

Specified by:

serializeWithType in interface com.fasterxml.jackson.databind.JsonSerializable

Throws:

IOException